


All Your Curves (And All Your Edges)

by maruya



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: AU, Angel Mercedes von Martritz, Dimitri Alexandre Blaiddyd Needs Sex Education, Dimitri Alexandre Blaiddyd Needs a Hug, Gen, Genderbending, Genderbent Dimitri Alexandre Blaiddyd, Let Dimitri Alexandre Blaiddyd Have a Life, Pre-Timeskip | Academy Phase (Fire Emblem: Three Houses), Prototyping, Seriously Mercedes is a Fucking Angel, andiwillwrite500more
Language: English
Status: Completed
Published: 2021-02-05
Updated: 2021-02-05
Packaged: 2021-03-17 04:27:52
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,031
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29219481
Author URL: https://archiveofourown.org/users/maruya/pseuds/maruya
Summary: Working to reign in the power of her Crest, Demeter gets into a rather sticky situation.Fem!Dimitri enjoys then despises her 18th birthday. Based on "All of You, All of Me" by andiwillwrite500more (prototyping)
Relationships: Dimitri Alexandre Blaiddyd & Mercedes von Martritz
Comments: 2
Kudos: 11





	All Your Curves (And All Your Edges)

**Author's Note:**

  * Inspired by [All of You, All of Me](https://archiveofourown.org/works/24705226) by [andIwillwrite500more (prototyping)](https://archiveofourown.org/users/prototyping/pseuds/andIwillwrite500more). 



> This story depicts a painful but non-violent situation regarding the vagina.
> 
> While this is a pre-timeskip prequel for “All of Me, All of You”, I suggest reading that first to understand fem!Dimitri’s characterization here.

“...a natural thing your body goes through,” a familiar voice explains behind the door. “The dreams manifest to help you regulate bodily fluids that would be detrimental if not rid of. There’s no need to feel guilty because it doesn't mean you intentionally..."

Demeter wants to cry—why would anyone be visiting Mercedes at this hour?!—but she couldn’t wait any longer. She has never liked the disparity of her title but she is willing to abuse it right now if she has to; she is going to throw that other person out back here like how she constantly threatens her own soldiers who would dare to even _look_ at Dedue funny. “Mercedes! Open up!”

It is a beat before the door reveals her fellow Blue Lion. Mercedes takes a breath but pauses. “Whatever is the matter, Demeter?”

“I need help. I cannot... walk all the way to the infirmary.”

Mercedes nods. “You had better come in. Oh, Professor, I’m sorry but we have to do this another time-”

“It can wait Mercedes. Thank you.” All sense of Demeter’s authority snaps in half like a twig. The Professor rises from a chair a respectful distance away from his student’s bed with a red face in ample candlelight—could he be dealing with a fever? But his expression means business when he says, “But Demeter, is this something I can help you with?”

 _No. No, no, no, this is all your fault, Professor, you told me you loved me and pledged yourself to me and pushed as much as I did and kissed as much as I did and that’s why now I..._ “No, Professor.” Demeter very self-consciously fixes the hair stuck to her forehead and straightens her nightgown, her sweat drying in the night... what if, what if she smells? She scrunches up her skirt behind her and winces at her wrinkled fingers: would the Professor know a female’s scent when he smells it?

“Then I won’t get in your way. You are excused from tomorrow’s classes if you do not get better immediately. I hope you be well. Goodnight.”

“Goodnight,” Demeter squeaks at the closing door.

“I see you are bleeding. Tell me what happened. Quickly,” Mercedes commands. “You know I won’t judge you, Demeter.”

Demeter mumbles, heart pounding in her ears and... herself fighting not to move around the foreign objects that had less than five minutes ago sent her into ecstasy. She watches Mercedes’s cerulean eyes grow wider. “I, I will do what I can. This will require intrusive sensing magic that will help me navigate your vaginal canal without seeing inside. At this point, it will be safer to use tools to remove the splinters for the first few pieces and assess your situation from there. Are you alright with that, or shall we go to Professor Manuela for more options?”

Worded out like that, Demeter gives up convincing she has only been feeling phantom pains. Is that a warm gush of blood crawling down her legs? “No, I don’t think I can move. Please help me...”

Mercedes’s emotions slip off her face as in battle. She motions for Demeter to stand by the table for support and hold up her skirts ( _but the Professor took them off himself tonight, slowly, giving her time to make him stop if she wanted_ ), and makes no comment on how the Crown Princess of Faerghus has no underwear on. She kneels and gently cups her liege’s crotch, sends a ray of white magic where Demeter had been touching herself all night. She frowns deeper. Pulls out what looks like a pair of nimble, delicate metal tongs from a pouch somewhere, and a small bottle of oil.

“This may sting, Demeter, but I need you to stay steady on your legs the entire time for me. I’ll do my best not to hurt you any further. We can take a break any time but you cannot sit down until this is over. Do you understand?'

“Yes.”

“Alright. Try to relax for me, there’s a love.”

It is memories of endurance training with Gustave and old competitions based on willpower with the Fraldarius brothers that convinces Demeter to grit her teeth and breathe an even pace in, in, out, in, in, out of her nose. Not the best pattern to follow. But it’s better than panicking out loud. She watches a spider on the ceiling corner walk up and down invisible thread. She feels the forceps slide into her, dragging (Mercedes makes every effort not to _scrape_ ) the wooden chips that have embedded themselves into her walls out, and the faint tap they make on the cloth that catches them on the floor. Demeter tries to follow the spider, count the wooden chips departing from her body to not drift and faint. Demeter thinks about the Professor. This wouldn’t have happened if he had been with her. He would kiss every little ache away (he himself fully... intact), carry her over to the toilet (to avoid infection Sylvain once said), carry her back and wash her down with a warm towel, wrap her up with him in a blanket, stroke her hair, call her his, and kiss her and kiss her and kiss her...

It is an eternity before Mercedes says, “You are doing splendidly, Demeter. My magic now might do more harm than good so I will keep using forceps. And we’re in luck. If they have splintered into finer pieces, we would have to get Professor Manuela to help. We’re halfway there, I’d say.”

Demeter is drunk on pain, willing to babble. “But she, she’s indisposed right now. Otherwise, the Professor wouldn’t have seen you this late.” Rage bubbles in her gut out of nowhere, offhand jealousy that has no place in this situation because he promised her, he promised her _as he moved against the ache between her legs to soothe his own, all desperate incoherence, that he has never felt this way for anyone, that she had awakened such maddening desire in him that crushes his restraint every time, that he cannot bear to only love with heart and mind anymore, he had to please her or he’ll never be satisfied, he’ll die if they stopped now, tell me you want me too, Demeter, please, tell me you love me, and she cries at the revelation and swears her all to him and,_

“Hmm. I... cannot talk much... dear, I have to concentrate. But if speaking helps you... ignore the discomfort... then you are free to bend my ear... although I may have to ask you to... repeat everything once I finish.”

Demeter winces. So rarely were her efforts at pleasure worth the slow and difficult build-up, curse her overpowering conscience. Until tonight, the only memorable orgasm she has had is her first (more surprising than enjoyable), and now, right after the best in her life, she stands wounded with her skirts up and not a sliver of dignity to preserve. Why would the Goddess, if She could be blamed, gift Demeter such monstrous power and such sensuous needs at the same time if not to punish her for... what exactly?

But, but it’s just not her Crest. It’s, well, everything. It starts with her birth and the body she is bestowed with, just like Mother’s, which had to be buried soon after. Father did not raise her to be a woman nor, wisely, a man—he raised her to be a soldier and ruler, kind and strong as such people must be, and he shielded her the best he could from all sense of shame for her sex or strength her entire childhood. Mother Patricia, as limited as her influence had been, taught by example: stand straight, keep your head up, look others in the eye and lift your skirts when you run or kick. Or simply change into pants. Never be smaller than you are no matter what they say or do; act in ways that make you happy, and your life’s important people will feel the same. Simple lessons Demeter cannot imagine trying to learn at her age now.

But the world, Demeter soon learned, did not just comprise of wonderful parents. Ingrid was her best friend even if she spent more time with Glenn and Felix because girls should be best friends with girls “so people don’t get ‘ideas’” according to Sylvain. Her combat instructor had once personally impaled a palace guard for telling her something she could no longer remember with a strange expression on his face, and Gustave had always refused to tell her why, only looking pained and assuring her it wasn’t her fault. When Edelgard arrived, Demeter was certain she wasn’t just a _best_ best friend with how her heart sang in her sister’s presence... They spent so many hours planning escape from future fiancés to a cottage in, say, Leicester where no one knew them or even Dagda, to paint and ride and make plans under the sheets late into the night; dance without the adults telling them to give the boys a chance together forever and ever. They never bothered wondering why they had to _escape_ in the first place. But Edelgard left and Demeter’s childhood ended. Sylvain, tall and perfumed Sylvain, began to make eyes at her but gave up entirely one day with an “I can’t do this, Your Highness, you’re too good for anyone!” and for the longest she believed herself despicable, having been rejected by the most handsome man in the universe. Glenn, kind as ever, kept respectable distance between them where there once had been none, and Demeter lied so many times that she wasn’t jealous when he redirected all his spare time to his rightful betrothed. Felix never failed to bicker with his brother when she was around: in fact, he fought with everyone roughly his age in her presence and looked away when she attempted eye contact. No one blamed these changes on her but she knew it was because they weren’t girls too—no, it was because _she_ was a girl. And after the world ended at Duscur, there were meetings with royal advisors who spoke of her status, her _existence_ as a liability to her face... unless maybe she acts more like a lady, Uncle Rufus adds... Godfather Rodrigue’s outcries ignored... Grief is a blur but Demeter’s clearest memory from the time is selfishness: she staggers through the palace pretending to weep with loss, hurrying before anyone sees the blood on her pants. The only woman Dedue could find who would not shame Demeter for her body then was Ingrid, poor, inexperienced Ingrid yet to be afflicted with womanhood, sobbing with her future Queen in panic as a Blaiddyd’s menarche tore through Demeter’s body the way _she_ could tear through others’. They cried the worst of it into pillows to keep the noise down, Demeter naked and shivering in the bath tub and Ingrid helplessly braiding her liege’s hair on a stool. No doctor was called, no adult consulted, and until Sylvain learned and told Cornelia against Demeter’s wishes, all Demeter had to help with the monthly torture was Ingrid’s supplies and Dedue’s red-faced but steadfast company. It takes magic and otherwise deadly concoctions to ease damage done by a Crest so destructive it is self-destructive... not enough magic or otherwise deadly concoctions to fix the damage she does in the first real battle she partakes. And that is a new issue to discuss, her performance in quelling the rebellion to the West: effective, certainly, but not satisfactory. Faerghus will not take lightly to a woman _and_ a beast on the throne, so the royal advisors decide to hide the Princess’s achievements from the Kingdom. And she kept trying to hide in the Academy except... Except. Except, except the Professor doesn’t want her to. The Professor, so beautiful in his skill and command and so unsure he is of himself around people until Demeter nudges him into mingling with her House, how he smiles because she taught him to—might as well have—Smiles not at her gender, title or Crest, but only ever her brute strength and long-honed skills, her determination, how she takes his lessons apart to absorb, her _soul._ That last factor alone is enough to bleed her logic out on cold nights, to fantasize, to _hope_ for a future where at least one person in the world has seen all of Demeter Alexandra Blaiddyd and not flinched, not left her side. A future where maybe, with one person, with _Byleth_ , she could unlearn all the shame she has been taught comes with being, the shame that comes with a heart and a body weak to basic human desire...

“...and that’s the last of it,” Mercedes announces. She runs the sensing spell into Demeter again and says “I'm going to insert two fingers in to heal you now. Okay?”

“Th-thank you.” Oh. That feels... but it’s over before she could think of a label.

“Now clench your muscles for me, please. Does it hurt or feel unusual anywhere?”

Demeter does as she’s told. She’s exhausted but her mind is clearer without the pain, more put together. Nothing feels out of place between her legs except the smarting that isn’t there anymore so she shakes her head.

“Well,” Mercedes sighs heavily, “We’re all done. That was not _quite_ the night I was expecting. Why don’t you make us some tea, dear, while I put these away?”

“Oh! Of course.” Demeter breathes one beat and pushes off the table. She isn’t used to people requesting things of her, but she is glad to help. As shaky as she is now, it’s really the least she could do.

Mercedes hands her a small silken package and moves away. Demeter blushes: a panty with magically absorbent cloth pad. She shouldn’t be embarrassed to borrow her comrade’s underwear _now_ but here she is, being her conservative self. Mercedes considerately takes her time boiling up water. She hands Demeter a cloth to go with it, for scrubbing off the blood that had already run down her thighs, and pours them both the tea.

“Well, Your Highness,” Mercedes assesses once they’d settled down, “I’ve missed quite a bit of your stories back there. Is there anything you’d like me to remember?”

“No,” Demeter protests too quickly. She recalls Mercedes humming at the wrong times throughout her internal monologue and realizes she _had_ been talking out loud... “I mean. No, thank you. Um.”

“Not a problem. It’s no matter to me. I’m just glad I could help you see it through.” Sweat sheens off Mercedes’s top lip as she flips the hair that had stuck to her nape off her flushed skin. Demeter takes a deep breath at the gesture. At the very least, her savior deserves an explana-

“If I may ask. Was that my birthday gift to you? I think I recognize the woodwork.”

Demeter bites her lip. Shrinks on herself. “Yes.”

“I am, well, flattered that you should be using it so... passionately.”

“Um. Asides. What people commonly. Buy it for. Er. My, my Crest strengthens my muscles. All of them. So I’m afraid, one day, if I were to, er, lie with a partner, I might accidentally...” Mercedes’s weary eyes grow awake again, mouth forming a small _o._ Demeter hurries before she loses her nerve, “In, in any case, I must prove—or disprove it—for myself. Before I accidentally, erm. Incapacitate someone.” And here she was now, in her classmate’s bedroom in the dead of night after very nearly incapacitating herself on a... on a, on a _sex toy._

“Of course! Silly me. I had completely forgotten all about your Crest, dear.” Inspired, Mercedes puts down her tea and opens Demeter’s free hand, tuts at the splinters she finds there. “I simply wanted you to, er, loosen up a bit. It must be... quite limiting,” (she finds some tweezers and makes work of the chips) “being raised as royalty so I... wanted to expand your horizons as a person. I should have bought you the steel one instead, but I thought it might be hard to use in Fhirdiad this time of year... oh, but I’m so glad I decided against the glass one!”

Demeter freezes. There are... _different materials_ for...? “Um.”

“I am glad you trust me, Demeter,” Mercedes adds, looking her future Queen in the eye. “It wouldn’t do to keep yourself in a state of pain in fear of what others might think. If you have any personal problems in the future, you can lay on me what you feel comfortable sharing.”

A breeze kills their candlelight through the window Mercedes had shut for privacy earlier. Moonlight glints off a spider web at the corner of the ceiling. Demeter’s heart beats in her throat. “I am so sorry for troubling you with my selfishness tonight. I have no excuse for wasting your time, but I will repent by refraining in the fut-”

“Demeter, dear, you have nothing to apologize for. I understand. And you’re not making any sense, you know. What else could I have given you a dildo but for selfishness’s sake?”

Mercedes, worn out for the day, dabs vulnerary on Demeter’s open hands. Strokes the future of Faerghus’s tousled blonde hair: a clean cut to make up for bloodied hands, a male’s cut to make up for missing parts. Demeter ducks to hide the rest of her weakness. “Thank you, Mercedes. From the bottom of my heart.”

“Oh, Your Highness. This is what friends are for.”

“It is... difficult to be...” No. That’s too personal. A ruler must command respect...  
  
“So it is. That’s why we are granted these bodies.”

Demeter blinks. “As punishment?

“Not at all. Imagine men bearing our burdens! They wouldn’t last a day. There is injustice only because we are taught to be people and call it being women, and boys believe that to be men they must be the opposite of women. No other reason for it. But perhaps in the future, we will see a Queen who will convince all of Faerghus to teach their children be good people before anything else.”

Demeter... couldn’t deny any of that. Funny. It’s something her mother would tell her now that she’s old enough to understand. “I... please, allow me to take over your chores for this week and the next. Oh, perhaps this whole upcoming month.”

“Would you, really? I’m not doing this for favors, you know.”

“I know. That’s why I offered a month.”

Mercedes giggles. “Then why not two weeks and one more favor? I want to be ruled by a Queen who keeps her heart in its right place. Faerghus, no, Fodlan would be happier land for it. And if I could help ensure that whatever way I can, keep me by your side. I would be glad to stay there.”

It is some time before Demeter regains composure. “I give you my word, Mercedes. I, I hope I could convince the rest of the Blue Lions to feel the same.”

“You already have! We’re here for you, Demeter. Just like you’re here for us.”

They finish the rest of their tea in cozy silence. How far Demeter has gone tonight, from anxiety and anticipation all day to raw lust to sheer horror to tears of relief that there are voices other than the ones in her head she could follow on her way forward.

But... would everyone she wants to be there...

“Demeter? Does it hurt still?”

“Oh, not at all! I was just wondering. The Professor was here earlier. Is he alright?”

“Oh, he is. Nothing serious. Yes, it’s quite a coincidence, isn’t it? He was here for the same thing.”

Demeter stares.

“Oh, but not _exactly_! No, it seems that the Professor is undergoing, um, growing pains. It’s hard to tell his age, but let’s just say he’s experiencing things for the first time as a young man might. He thought it was a medical emergency and came to me.”

“O-oh.” Demeter bites the inside of her cheek, feeling like she had pried more than was right. Now that that her avalanche of hormones has dissipated, she couldn’t even begin to... imagine the Professor’s body experiencing innocent changes.

Mercedes yawns politely and Demeter is reminded of the time. “He dreams of you, you know.”

“Excuse me?”

“Oh, I meant your destined beloved. They are out there, dreaming of you. Wishing you would come to them and give your all, accept their all. And they _won’t_ be damaged or hurt by your Crest. I’m certain of it.”

“That is a happy thought but I mustn’t bother you further, Mercedes. The day begins in a few hours.”

“Oh, Demeter. If the bleeding doesn’t stop or if anything feels wrong, come to me or Professor Manuela immediately. And I recommend resting tomorrow at least until after lunch break. Your body needs to recover from the memory of the trauma too. Don’t worry about the others or getting a medical slip. I’ll tell them you are recovering from an injury.”

“I’ll... think about it. Thank you kindly, Mercedes. Good night.”

“Good night.”

Demeter walks to her room barefoot, warm within the shawl Mercedes insisted she take. She doesn’t remember how she managed to run down the hall and scramble down two flights of stairs in her state hours before, but it could be that her appalled body chose not to.

A movement on the far side of the dormitories... oh. The Professor is coming back from the bathhouse. He shivers in his sleepwear and steam seems to be rising from his head... had he just taken a cold shower? But, but the words _Byleth_ and _shower_ have no place in Demeter’s head now, not when she’s already worrying about recalling inappropriate things at an inappropriate time. For example, when they next speak.

Demeter throws her windows wide open and uses a scented candle (molded by Dedue using a Duscur plant with muscle relaxing properties) to exhume what was left of her... smell. She changes out of her nightgown, replaces the sheets, wipes herself down with a damp towel and washes her short hair. The pad looks like the last couple days of her period, which she assumes is healthy; she’ll wash the undergarment itself tomorrow. She dreads performing such a delicate task but denying Mercedes basic courtesy after tonight would be nothing short of criminal. And there’s her nightgown and the sheets to take care of too... should she wash them on her own to keep the laundrywoman from knowing what she had done?

But she is too tired to feel guilty, to plan acting based on guilt. Her head is a blur with the day: finishing her notes from last night’s research on her uncle, written exams and jousts, the Professor inviting her for tea (and how her heart raced!), her usual brutal training routine, the little feast Blue Lions threw her for dinner, their gifts and affection she is working so hard to deserve, her experiment and the consequence, cooling lavender tea with the saint who told her her injuries are perfectly understandable and worth treating, and assured her she is sane... Demeter doesn’t have the strength to experience anything more, except maybe realize that if someone would help her in the end, maybe it was alright to live life as she sees fit.

She covers her head Mercedes’s shawl, just in case the voices decide to come back before she falls asleep. They’ve been mysteriously absent—shocked into silence, probably—since she unwrapped _that_ particular present in her room after dinner but other than that and skipping on research, it’s just another day. In bed she’s just another tired soul pretending the pillow is somebody else. Her and Byleth. Naked as the day they were born and just as innocent. They keep each other warm snug within her favorite quilt in the Palace, and he runs his hands through her long, long hair. There is nothing wrong with that. Nothing wrong in the world. Nothing at all...

Demeter fades into a deep and dreamless sleep.

**Author's Note:**

> I read AoMAoY and thought huh, would be hot if fem Dimitri just snaps all her toys in half. Then my stupid realist brain went actually you can’t cleave wood perfectly in a solid block and also a character study of a girl with too much responsibility on her shoulders struggling with her sexuality and finding comfort in an older sister figure who treats her as an equal would be super wholesome.  
> Demeter is a teenager in a patriarchal society LEAVE HER ALONE. Also Byleth has no hormones until Sothis awakes.
> 
> Many thanks to Jay aka  
> [@prototyping](https://archiveofourown.org/users/prototyping/pseuds/prototyping) and [@andIwillwrite500more](https://archiveofourown.org/users/prototyping/pseuds/andIwillwrite500more) for letting me write based on their story! They write fluff and characters (Demeter!!) extremely well so give their works a spin.


End file.
